|Publication number||US20050157653 A1|
|Application number||US 10/828,333|
|Publication date||Jul 21, 2005|
|Filing date||Apr 21, 2004|
|Priority date||Jan 16, 2004|
|Publication number||10828333, 828333, US 2005/0157653 A1, US 2005/157653 A1, US 20050157653 A1, US 20050157653A1, US 2005157653 A1, US 2005157653A1, US-A1-20050157653, US-A1-2005157653, US2005/0157653A1, US2005/157653A1, US20050157653 A1, US20050157653A1, US2005157653 A1, US2005157653A1|
|Inventors||Reuven Zeitak, Uri Avigad|
|Original Assignee||Native Networks Technologies Ltd.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (3), Referenced by (7), Classifications (14), Legal Events (2)|
|External Links: USPTO, USPTO Assignment, Espacenet|
The present invention claims priority from U.S. Provisional Patent Application No. 60/536,737, filed 16 Jan. 2004.
The present invention relates to data networks, and more particularly to methods for accounting for network traffic overhead.
Network traffic often travels over buses in the form of data packets or frames (both referred to hereafter as “packets”), each including a variable data payload that a source station sends to a destination station. Each packet also includes a header conveying data that the network devices need for the purpose of properly routing and processing the packet.
A network node (e.g., a switch, a router, a gateway, etc.) passes data packets received from a source station to a destination station based on the header information in the packet. The header portion, as shown in
The Ethernet protocol clearly defines for Ethernet packets the beginning and the ending boundaries or “delimiters”. These are marked by special characters and by an inter-packet gap (IPG) overhead 110. IPG overhead 110 includes a fixed number of bytes that dictate the minimum space or “idle time” between the transmission of two consecutive packets. The size of IPG overhead 110 affects the available bandwidth, i.e., increasing the size of the IPG overhead 110 decreases the available bandwidth.
When the Ethernet traffic is transmitted over non-Ethemet networks such as synchronous digital hierarchy (SDH) networks or synchronous optical network (SONET) networks, the IPG overhead (e.g., IPG overhead 110) is removed from the Ethernet packets before being transmitted on the network. This is done by a device connected on a network access node called a “rate regulator”. The rate regulator is mainly used for policing data traffic (e.g., to control the bandwidth) and for transmitting packets to the network. After handling by the rate regulator, packets received on an egress port of a destination station are aggregated, and for each packet the IPG overhead is added. The number of extra bytes to be added to a packet is determined by the IPG demands of the Ethernet protocol. For example, the number of IPG bytes for 10 Mbps and 100 Mbps is 12 bytes and an additional 8 bytes of preamble overhead, to give a total of 20 overhead bytes. Adding the IPG overhead at the egress port, i.e. not counting the IPG overhead at the rate regulator, impacts the network performance and the committed quality of service (QoS).
Referring now to
This problem can be resolved by configuration of rate regulator 220 to transmit packets at rate lower than the rate complying with egress port 230. The rate to transmit the packet can be calculated according to the following equation:
Rate=E-Rate*(packet size)/(packet size−[IPG+preamble overhead size]); (1)
where the E-rate is determined by the type of egress port 230 (e.g., 10 Mbps for 10BaseT). The packet size is the minimum length defined for a packet. Consequently, as a packet may be received in different sizes, pre-configuring rate regulator 220 to transmit packets at a rate designated by equation (1) may underutilize the bandwidth of egress port 230. For example, long packets will receive a rate lower than 10 Mbps.
We refer now to
A rate regulator may use several policing or shaping schemes to regulate the rate. These policing schemes may be three color marker, leaky bucket, adaptive leaky bucket, one bucket two colors, etc. The shaping schemes may be leaky bucket, dual leaky bucket and others. However, all of these policing and shaping schemes ignore the size of the IPG overhead when performing rate enforcement, and thus all the problems introduced above are not eliminated.
Therefore, it would be an advantageous to provide a solution that would efficiently resolve the limitations and shortcomings of the prior art.
The present invention provides a method and device for charging for uncounted network traffic overhead. The invention allows service providers to charge users for uncounted overheads as part of the bandwidth users pay for. Alternatively, the invention provides the user with the actual bandwidth paid for inclusive of the overhead bytes. As a result, a node transmitting small packets and hence requiring relatively a high IPG overhead will either pay more for the bandwidth to account for the additional bandwidth it consumes, or otherwise be limited to the bandwidth actually paid for inclusive of the IPG overhead packets.
According to the present invention there is provided a method for charging for uncounted network traffic overhead, the traffic carried by data packets in a plurality of data paths, the method comprising the steps of: providing a rate regulator having a regulator bandwidth coupled to a respective ingress port, the rate regulator operative to regulate the rate of a data path established over a network between the respective ingress port and an egress port having an egress port bandwidth; determining a respective overhead criterion for the data path; and configuring the rate regulator with the respective overhead criterion to charge for uncounted overhead, whereby each data packet transmitted through the rate regulator is handled as a packet that has additional bytes as determined by the overhead criterion, thereby ensuring that the regulator bandwidth does not exceed the egress port bandwidth.
According to the present invention there is provided a network rate regulator having a regulator bandwidth and used for regulating data packet traffic carried on a data path established over a network between an ingress port and an egress port, the egress port having an egress bandwidth, the regulator comprising: a criterion determining mechanism for determining an overhead criterion for the data path; and a configuring mechanism for configuring the rate regulator with the overhead criterion to charge for uncounted overhead, whereby each data packet is handled as a packet that has additional bytes as determined by the overhead criterion, thereby ensuring that the regulator bandwidth of the rate regulator does not exceed the egress port bandwidth.
The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein:
We refer now to
Packets transmitted from a source node 410 to a destination node 460 are limited by fixed bandwidth using a rate regulator 430, but the sizes of the overheads of the packets vary as the packets travel through system 400.
The present invention performs uncounted overhead charging at rate regulator 430 using an overhead criterion. The overhead criterion defines the maximum difference size between an output overhead of packet 520 and an input overhead of packet 510 traveling along the path established between an ingress port of a rate regulator (e.g., packet 430-1) and an egress port (e.g., packet 450-m). This difference is fixed for all packets and defined by the Ethernet protocol standard. For example, if the input overhead is 32 bytes and the output overhead is 52 bytes, the overhead criterion is equals to 52−32=20 bytes. The overhead criterion may be a function of some or all of these factors: the ingress port, the egress port, the rate regulated by the rate regulator, and the packet size. Once the overhead criterion is determined, the rate regulator is configured to charge according to the overhead criterion. That is, the number of bytes designated by the overhead criterion is taken into account as if they were part of the input overhead. This ensures that the bandwidth of rate regulator 430 does not exceed the bandwidth of egress port 450. An exemplary and non-limiting formula for calculating the overhead criterion is:
where INS is the size of an input packet at an input of the network, OUTS is the size of an output packet of an egress port, and Φ is a rate factor. The rate factor Φ is equal to ‘1’ if the rate of the ingress port at a source node is higher than the rate of an egress port at a destination node. Otherwise, rate factor Φ is equal to ‘0’.
For illustration, refer back to the example discussed in
The inventors note that the disclosed method for overhead charging allows service providers to charge users for uncounted overheads as part of the bandwidth users pay for. Alternatively, the disclosed method provides the user with the actual bandwidth paid for inclusive of the overhead bytes. As a result, a node transmitting small packets and hence requiring a relatively high IPG overhead will either pay more for the bandwidth to account for the additional bandwidth consumed, or will otherwise be limited to the bandwidth actually paid for inclusive of the IPG overhead packets.
We refer now to
The inventors note that the overhead charging method disclosed herein can be utilized by any policer or shaper known in the art. In particular, the overhead charging method can be executed by the policer disclosed in a co-pending U.S. patent application No. 60/535, 507 entitled “A Policer and Method for Resource Bundling” assigned to the common assignee and which is hereby incorporated by reference. We further note that the overhead criterion as disclosed herein may be used by any policing or shaping algorithms known in the art. In particular, the overhead criterion may be used in the shaping algorithms described in U.S. patent application Ser. No 09/572,194, filed Feb. 5, 2001, entitled “Multi-Level Scheduling Method for Multiplexing Packets in a Communications Network”, assigned to common assignee and incorporated herein by reference.
All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.
While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made.
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|Citing Patent||Filing date||Publication date||Applicant||Title|
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|International Classification||H04L29/06, H04L12/26, H04L12/14, H04L12/56|
|Cooperative Classification||H04L69/22, H04L47/10, H04L47/20, H04L12/1425, H04L12/14|
|European Classification||H04L47/10, H04L12/14F, H04L47/20, H04L12/14|
|Apr 21, 2004||AS||Assignment|
Owner name: NATIVE NETWORK TECHNOLOGIES LTD., ISRAEL
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:ZEITAK, REUVEN;AVIGAD, URI;REEL/FRAME:015252/0966
Effective date: 20040418
|Apr 7, 2006||AS||Assignment|
Owner name: ALCATEL, FRANCE
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:NATIVE NETWORK TECHNOLOGIES, INC.;REEL/FRAME:017434/0641
Effective date: 20060119